Security readout for executives and security teams
Plain-English summary
CVE-2019-1816 affects Cisco Web Security Appliance. A logged-in local attacker could abuse insufficient input validation in the log subscription feature to run operating-system commands and gain root privileges. It is not described as remotely exploitable without authentication, but compromise of a WSA can affect a security control point.
Executive priority
Treat as a moderate-priority security appliance hardening issue. It is not documented as internet-scale unauthenticated exploitation, but a malicious or compromised account could gain root access on a device that may process sensitive web traffic and enforce policy.
Technical view
The flaw is command injection in the Cisco WSA log subscription subsystem, reachable through the web and command-line interfaces. Cisco attributes it to insufficient validation of user-supplied input. CVSS 3.0 is 5.3 with local access, low complexity, low privileges, no user interaction, unchanged scope, and low CIA impact.
Likely exposure
Exposure is limited to organizations running Cisco Web Security Appliance where an attacker has local authenticated access to the device interface. The source bundle does not identify affected or fixed version numbers, so asset owners must compare their deployed releases against Cisco guidance.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. Exploitation requires authentication and local access, but the post-exploitation result is serious because successful abuse can elevate privileges to root on the appliance.
Researcher notes
The core weakness is CWE-20 input validation failure leading to command injection in the log subscription subsystem. The public bundle lacks fixed-version details and exploit telemetry. Validation should focus on authenticated access paths, configuration exposure, and whether Cisco-published remediation applies.
Mitigation direction
- Check Cisco advisory for affected releases and fixed software guidance.
- Restrict WSA administrative and CLI access to trusted users and networks.
- Remove unnecessary local accounts and reduce excessive privileges.
- Monitor WSA logs for unexpected log subscription changes.
- Prioritize remediation where WSA administration is broadly accessible.
Validation and detection
- Inventory all Cisco Web Security Appliance deployments.
- Compare deployed versions against Cisco advisory details.
- Verify who can authenticate to web and command-line interfaces.
- Review whether log subscription changes are restricted and audited.
- Check historical logs for unusual administrative activity.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-20: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupPrivilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2019-1816 mapping review
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Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.3 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L1.83.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
5.3MediumVector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Source materials
- CVE List V5 sourceCVE List V5
- 20190501 Cisco Web Security Appliance Privilege Escalation VulnerabilityCVE reference · vendor-advisory, x_refsource_CISCO
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Input Validation
Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.